<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>作业</title>
</head>
<body>
    <script>
        var name = prompt("请输入您的姓名:");
        console.log("用户的姓名是：" + name);
        var sex = prompt("请输入您的性别：")
        console.log("用户的性别是：" + sex);
        var age = prompt("您现在多少岁了？")
        console.log("用户的年龄是：" + age);
        alert('据我估计，五年后，你应该是' + (Number(age)+5) + "岁")

        // var a = 1 ,b=2;
        // a = a + b //a=3
        // b = a - b   //b=1
        // a = a - b // a=2   skdjfskdjfslkdfj
    </script>
</body>
</html>